1. Field of the Invention
The present invention relates generally to a mobile communication system, and in particular, to providing a roaming service among private mobile switching centers.
2. Description of the Related Art
In general, private (or local) mobile switching centers (MSCs) provide the mobile communication service only to the mobile subscribers registered therein. Therefore, the mobile subscribers cannot be provided with the mobile communication service, when they move into a service area (or coverage area) of a private mobile switching center in which they are not registered. That is, a mobile subscriber registered in a certain private mobile switching center can be provided with a call originating service, a call terminating service and other additional services only in a service area of the private mobile switching center.
Utilization of a virtual private network in a mobile communication system is described in the following references, incorporated by reference herein: U.S. Pat. No. 6,029,067 to Matthias Pfundstein entitled Virtual Private Network for Mobile Subscribers; U.S. Pat. No. 6,101,382 to Christer Granberg entitled Transfer of Calling Party Identification in a Mobile Communication System; and U.S. Pat. No. 6,175,622 to Sima Chiniwala et al. entitled Virtual Private Network for a Telephone Network.